Around AD 540, the Abbey of
Mynyw (St. Davids) was founded by St. David,
the grandson of a local chieftain,
in the Rhoson Uchaf (Rosina Vallis) in modern-day Pembrokeshire.
Despite opposition from an Irish warlord who had settled in the area,
David established a thriving community protected in a hollow between the
hills.

Ancient legend says that Wales
always had an archiepiscopal see. Originally this was supposed to have
been at Caerleon. However, about five
years after moving to Mynyw, St. David spoke so eloquently against the
Pelagian heresy at the Synod of Brefi (at Llandewi Brefi), that St.
Dyfrig gave up the Archbishopric in his favour. David accepted
and, naturally enough, decided to transfer his cathedra to his own
monastery at Mynyw (St. Davids). The place has remained a cathedral city
ever since: the smallest in Britain.